Natural gas is not the 'panacea' the fossil fuel lobby would like to present, says the IEA. Photograph: Oli Scarff/Getty Images

Natural gas is not the "panacea" to solve climate change that fossil fuel industry lobbyists have been claiming, according to new research from the International Energy Agency (IEA).

Gas is likely to make up about one-quarter of the world's energy supply by 2035, according to the study, but that would lead the world to a 3.5C temperature rise. At such a level, global warming could run out of control, deserts would take over in southern Africa, Australia and the western US, and sea level rises could engulf small island states.

Nobuo Tanaka, executive director of the IEA, told a press conference in London: "While natural gas is the cleanest fossil fuel, it is still a fossil fuel. Its increased use could muscle out low-carbon fuels such as renewables and nuclear, particularly in the wake of Fukushima. An expansion of gas use alone is no panacea for climate change."

Governments are likely to come under pressure to reduce support for low-carbon energy and opt for gas instead, as oil and gas companies have been urging, in a move that could imperil the fight against climate change, the IEA warned.

Fatih Birol, chief economist of the IEA and one of the world's foremost authorities on energy and climate, said: "If gas prices come down, that would put a lot of pressure on governments to review their existing renewable energy support policies ... We may see many renewable energy projects put on the shelf."

He said some renewable technologies, such as onshore wind, would continue to prosper but the worst affected projects were likely to be offshore wind and solar energy.

Birol said the world must continue to invest in renewables, energy efficiency and carbon capture and storage, in order to stave off climate change. If the world fails to invest in renewables, a new generation of gas-fired power stations would have a lifetime of at least 25 years, effectively "locking in" billion of tonnes of carbon emissions a year.

The Guardian recently revealed the extent of lobbying by the gas industry, which senses a unique opportunity to rebrand itself as green. Previously inaccessible sources of gas, known as "unconventional" gas, are predicted to create a "golden age of gas" with lower prices and plentiful supply.

When burned for power, gas produces half the carbon of coal. However, a recent study from Cornell University suggested that this might not be the full story, as using shale gas - one of the chief forms of "unconventional" gas, derived from fracturing dense rocks - could create more emissions than coal because of difficulties in its exploitation. The IEA's estimates put the associated emissions much lower.

Along with a supply glut - the IEA estimates there are at least 250 years of recoverable resources at today's demand levels - gas is benefitting from market turmoil surrounding some of the alternatives. "Gas is a fortunate fuel because all its competitors have some problems," said Birol.

Coal suffers high emissions, renewables can be expensive, and there are safety fears over nuclear after the Fukushima disaster in Japan.

But Birol pointed to evidence that exploiting unconventional gas could bring severe environmental damage. In the US, there are many reports of contamination in the water supply near shale gas sites, and dangerous leaks of natural gas. In the UK, two small earthquakes have taken place near sites where a company is using "fracking" - the process of releasing gas from dense shale rocks by blasting it with water and chemicals. Fracking operations have been halted while investigations take place to establish whether there is a link.

Birol said that the concerns around fracking should lead companies to adopt more stringent safety and environmental measures.

"If gas companies want to see a golden age of gas, then they need to stick to golden standards," he said.